was observed to fit this data well with a correlation coefficient of 0.9950.
Thus, Ferraz (26) concluded that the dual-energy gamma attenuation
method is a sensitive means to determine soil water content.

 2. Sensitivity of the Method for Determination of
 Soil Bulk Density
 Ferraz (26) used 41 samples of 11 different soils with bulk densities
ranging between 0.989 and 1.733 g/cm3 to determine the sensitivity of
the dual-energy gamma attenuation method for determining soil bulk
density. The soils were first dried at 1050 C for 3 days, then the sam-
ples were prepared with homogeneous compaction and the actual density




E7
u 1.6




C3 "
 ~ *0






 n -
 S1.0

 1O. .*
 0




 1.0 1.2 1.4 1.6

 Experimental Bulk Density, p (g/cm3)

Figure 11. Sensitivity of soil bulk density determinations for 41 samples
from eleven soils. The actual density, d, was determined by weighing and
the experimental bulk density, p, was determined by dual-energy gamma
attenuation (Ferraz, 26). The straight line was determined by linear re-
gression (r=0.989).